METHOD FOR OPERATING AN ELEVATOR SYSTEM AND ELEVATOR SYSTEM DESIGNED FOR PERFORMING THE METHOD

Abstract

The present disclosure concerns a method for operating an elevator system which comprises a shaft system and at least three cars, which is designed for separately moving the cars in at least a first direction of travel and in a second direction of travel. The at least three cars are moved separately in sequential operation each time and for each car a stop point at which the car can stop if necessary is continuously predicted at least for one direction of travel. The distance of the predicted stop points of neighboring cars from each other is thereby continuously determined. The elevator system is transferred to a safety mode if a negative distance of the stop points is determined.

Claims

1-11. (canceled)

12. A method for operating an elevator system which comprises a shaft system and at least three cars, the elevator system configured for separately moving the cars in at least a first direction of travel and in a second direction of travel, the method comprising: moving the at least three cars separately and sequentially; continuously predicting a stop point for each car of the at least three cars for at least one direction of travel; continuously determining a distance of the predicted stop points of neighboring cars from each other of the at least three cars; and transferring the elevator system to a safety mode based on a negative distance of the stop points being determined.

13. The method of claim 12, further comprising: predicting a stop point of each car of the at least three cars under an assumption of the stopping of the respective car at latest upon engagement of at least one safety mechanism of the elevator system.

14. The method of claim 13, further comprising: predicting a stop point of each car under an additional assumption that the respective car is accelerated with the maximum possible acceleration on the part of the elevator system before the engaging of the at least one safety mechanism of the elevator system.

15. The method of claim 12, further comprising: predicting for each car a first stop point for the first direction of travel; and predicting for each car a second stop point for the second direction of travel such that two stop points are predicted continuously for each car.

16. The method of claim 15, further comprising: determining a distance for each car having a neighboring first car in the first direction of travel from the first stop point of the car to the second stop point of the neighboring first car.

17. The method of claim 16, further comprising: determining a distance for each car having a neighboring second car in the second direction of travel from the second stop point of the car to the first stop point of the neighboring second car.

18. The method of claim 12 wherein each car of the elevator system has their own control unit, the method further comprising: predicting, with the respective control unit of a first car, a stop point for the at least one direction of travel; transmitting predicted stop points for each car of the at least three cars to control units of neighboring cars of the at least three cars; and ascertaining, with the respective control unit of an identified car, a distance of the stop points predicted for the first car from the stop points transmitted to the control unit of the first car.

19. The method of claim 18, further comprising: triggering a safety mechanism of an identified car upon determining a negative distance of the stop points with the respective control unit; and bringing the identified car to a halt based on the triggering.

20. The method of claim 19 wherein the stop points are predicted each time from current operating parameters of the respective car.

21. The method of claim 19 wherein the elevator system comprises a decentralized safety system with a plurality of control units, wherein the plurality of control units comprise the control units of the cars, the method further comprising: exchanging data with the control units; and determining an operating mode deviating from normal operation of the elevator system.

22. An elevator system comprising: a shaft system having at least one shaft; at least three cars that move separately in at least a first direction of travel and in a second direction of travel in the at least one shaft of the shaft system; a control unit associated with each car of the at least three cars; wherein the at least three cars are moved separately in sequential operation, wherein a stop point at which each car can stop if necessary is continuously predicted at least for one direction of travel of the first and second directions of travel; wherein a distance of the predicted stop points of neighboring cars from each other is continuously determined and the elevator system is transferred to a safety mode based on a negative distance of the stop points is determined.

23. The elevator system of claim 22 wherein the stop point of each car is predicted each time under the assumption of the stopping of the respective car at latest upon engagement of at least one safety mechanism of the elevator system.

24. The elevator system of claim 23 wherein the stop point for each car is predicted under the additional assumption that the respective car is accelerated with the maximum possible acceleration on the part of the elevator system before the engaging of the at least one safety mechanism of the elevator system.

25. The elevator system of claim 24 wherein a control unit of an identified car of the elevator system each time predicts the stop point for the at least one direction of travel and each time the stop points predicted for the identified car are transmitted to the control units of the neighboring cars.

26. The elevator system of claim 25 wherein stop points of neighboring cars are transmitted to the identified car and wherein the control unit of the identified car ascertains the distance of the stop points predicted for the identified car from the stop points transmitted to the control unit of the identified car.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0034] Further advantages, features, and design details of the invention shall be explained more closely in conjunction with the sample embodiments shown in the figures. There are shown:

[0035] FIG. 1 in a simplified schematic representation, a sample embodiment of an elevator system, which is operated according to a variant embodiment of a method according to the invention; and

[0036] FIG. 2 in a simplified schematic representation, a sample embodiment of a car for use in an elevator system represented in FIG. 1, with example stop points shown.

DETAILED DESCRIPTION

[0037] The elevator system 1 represented in FIG. 1, which for reasons of clarity is not drawn true to scale, comprises a shaft system 2 with two vertical shafts 12 and two connecting shafts 13. Furthermore, the elevator system 1 comprises a plurality of cars 3 (eight cars for example in FIG. 1), which can be moved separately in a sequential operation in the shaft system 2, that is, several cars 3 can be moved in a shaft 12 or a shaft 13.

[0038] The cars 3 can move upward in the shafts 12 in a first direction of travel 4 (shown symbolically in FIG. 1 by the arrow 4) and downward in a second direction of travel 5 (shown symbolically in FIG. 1 by the arrow 5). In the connecting shafts 13, by which the cars 3 can switch between the shafts 12, the cars are furthermore laterally movable in a third direction of travel 10 (shown symbolically in FIG. 1 by the arrow 10) and in a fourth direction of travel 11 (shown symbolically in FIG. 1 by the arrow 11).

[0039] In particular, it is provided that the elevator system comprises, as its drive system, at least one linear motor (not shown explicitly in FIG. 1), by means of which the cars 3 travel within the shaft system 2.

[0040] The elevator system 1 represented in FIG. 1 is operated in such a way that, for each car 3, in ongoing fashion a first stop point 6 is predicted for the first possible direction of travel and a second stop point 7 for the second possible direction of travel. Thus, for each car 3 a stop point is predicted in ongoing fashion for at least one direction of travel. Thus, for cars 3 located in the vertical shafts 12 an upper stop point is predicted as the first stop point 6 and a lower stop point is predicted as the second stop point 7. In the connecting shafts 13, a stop point located in the direction of travel of the respective car 3 is predicted as the stop point 6′ and a second stop point located opposite the direction of travel of the respective car 3 is predicted as the stop point 7′.

[0041] The stop points can be defined in particular by coordinates (x, y), wherein lateral stop points are defined by the x-coordinates and vertically situated stop points by the y-coordinates. For example, the coordinates (0, 0) can be assigned to the point A in FIG. 1 for example.

[0042] The two stop points 6, 7 or 6′, 7′ indicate for each of the possible direction of travel s 4, 5 or 10, 11, starting from the current position of the respective car 3, each time the point at which the car 3 can stop at latest, assuming a worst case scenario. In particular, for a car 3′ moving upward, taking into account current operating parameters such as for example the direction of travel, speed, and loading capacity of the car 3′, an upper stop point 6 is predicted, i.e., determined in advance, where the car 3′ would stop if the car 3′ were accelerated to the maximum in the direction of travel and then braked. As the lower stop point 7 of the car 3′, under the worst case assumption, it is predicted that the drive fails, the car 3′ as a result of this slumps down, and only then is the car 3′ braked.

[0043] Corresponding predictions are done in ongoing manner for the other cars 3 of the lift system. Advantageously the cars 3 comprise a control unit for this, for example, a microcontroller circuit designed as a control unit (not explicitly shown in FIG. 1).

[0044] For each car 3 having a neighboring first car in a first direction of travel, the distance from the first stop point 6 of this car to the second stop point 7 of the second car is determined. Furthermore, for each car 3 which has a neighboring second car in the second direction of travel, the distance from the second stop point 7 of this car to the first stop point 6 of the second car is determined.

[0045] For example, for the car 3′ which has a neighboring car 3″ in direction of travel 4, the distance 8 from the upper stop point 6 of the car 3′ to the lower stop point 7 of the car 3″ is determined. For this, advantageously the lower stop point 7 of the car 3″ is transmitted to a control unit (not explicitly shown in FIG. 1) of the car 3′. The distance 8 so determined is positive in this example. Thus, no collision danger exists in regard to the cars 3′ and 3″.

[0046] The car 3′ furthermore has a neighboring car 3′″ in the other direction of travel 5. Therefore, the distance 9 from the lower stop point 7 of the car 3′ to the upper stop point 6 of the car 3′″ is furthermore determined for the car 3′. For this, advantageously the upper stop point 6 of the car 3′″ is transmitted to a control unit (not explicitly shown in FIG. 1) of the car 3′. The distance 9 so determined is negative in this example, that is, the upper stop point 6 of the car 3′″ lies above the lower stop point 7 of the car 3′. Thus a collision danger exists in regard to the cars 3′ and 3′″. On account of the negative distance 9 of the lower stop point 6 of the car 3′ and the upper stop point 7 of the car 3′″, the elevator system is transferred to a safety mode, especially by activating a car-side braking of these cars, preferably triggered by the control units coordinated with the respective cars 3′ and

[0047] Since each time only one stop point is transmitted to a car 3 from the two neighboring cars, the communication load in the method applied is advantageously slight.

[0048] For a further explanation of the stop points which are predicted for a car 3 according to a method of the invention, refer to FIG. 2. FIG. 2 shows a car 3 with an overall car height 17 and an entry threshold 20.

[0049] For the car 3 which can move in direction of travel 4 and in direction of travel 5 (in FIG. 2 the direction of travel is shown symbolically by arrows 4, 5), each time a predicted stop point 6, 7 is shown for each direction of travel 4, 5 for example. For the direction of travel 4, the upper stop point 6 is shown, and for the direction of travel 5 the lower stop point 7.

[0050] The upper stop point 6 indicates the point where the car 3 can stop at latest in the direction of travel 4 with the upper car end 21, based on current operating parameters and assuming a worst case scenario. The distance between the stop point 6 and the upper car end 21 in the sample embodiment depicted results from the sum of an optionally established minimum distance 15 to the car 3, which must not be crossed, and a braking distance 18 calculated from the current travel parameters assuming a worst case scenario. The calculation of the stop points is done for example by means of a correspondingly configured predictor model.

[0051] The lower stop point 7 on the contrary indicates the point where the car 3 can stop at latest in the direction of travel 5 with the lower car end 22, based on current operating parameters and assuming a worst case scenario. The distance between the stop point 7 and the lower car end 22 in the sample embodiment depicted results from the sum of an optionally established minimum distance 16 to the lower car end 22, which must not be crossed, and a braking distance 19 calculated from the current travel parameters assuming a worst case scenario.

[0052] The positions of the stop points vary in dependence on the current respective operating parameters. If the car is halted, the stop points will move closer to the car. If the car is traveling upward at high speed, i.e., in direction of travel 4, the upper stop point will lie further above. In particular, even at very high speed the case may occur that the lower stop point 7 will be determined lying at position 14, since in this case a movement in the direction of travel 5 can be ruled out, even in the worst case scenario.

[0053] For each such car 3 as represented in FIG. 2, each time such an upper stop point and a lower stop point is predicted. Each time the distance between the upper stop point 6 of a car and the lower stop point 7′ or 7″ of a neighboring car located above this car and the distance between the lower stop point 7 of this car and the upper stop point 6′ or 6″ of a neighboring car located below this car is determined. During a non-critical operation, the distances 8 are positive, since 7″ is greater than 6 and 7 is greater than 6″. In the case of a negative distance, on the other hand, there is a collision risk. Such a negative distance occurs if 6 is greater than 7′ or 6′ is greater than 7. If such a negative distance is determined, the elevator system will be transferred to a safe operating state, especially to a safety mode.

[0054] The sample embodiments represented in the figures and explained in connection with them serve to explain the invention and are not limiting to it.

LIST OF REFERENCES

[0055] 1 Elevator system [0056] 2 Shaft system [0057] 3 Car [0058] 3′ Car [0059] 3″ Car [0060] 3′″ Car [0061] 4 First direction of travel [0062] 5 Second direction of travel [0063] 6 First stop point [0064] 6′ First stop point [0065] 6″ First stop point [0066] 7 Second stop point [0067] 7′ First stop point [0068] 7″ First stop point [0069] 8 Positive distance of predicted stop points [0070] 9 Negative distance of predicted stop points [0071] 10 Third direction of travel [0072] 11 Fourth direction of travel [0073] 12 Vertical shaft [0074] 13 Connecting shaft [0075] 14 Extreme position for a possible stop point [0076] 15 Minimum distance to be maintained from the car [0077] 16 Minimum distance to be maintained from the car [0078] 17 Car height [0079] 18 Predicted braking distance [0080] 19 Predicted braking distance [0081] 20 Entry threshold [0082] 21 Upper end of car [0083] 22 Lower end of car